A would-be assailant throws a punch. With a slip of the hips and head, Jason Moreno slides under the punch, takes the attacker’s free wrist, steps through and behind his opponent, and easily takes him to the ground while maintaining control of the altercation. Moreno, a brown belt in the martial art of jiu-jitsu, is a 20-year-old Cadet at the Tustin Police Department who hopes to become a police officer with the agency. He took up the sport six years ago to recuperate from illness and rebuild his cardiovascular health. He now helps teach officers about the form of the…